Potassium citrate is a common sensitive toothpaste ingredient whose purpose is to reduce teeth sensitivity by depolarizing the nerve. It is often found in sensitive toothpastes due to its desensitizing properties but it also has a couple of other uses. We will explain how it works as well as potential adverse effects.
Molecular structure - K3C6H5O7
Color: White
Texture: Hygroscopic (water absorbent) crystalline powder
Smell: Odorless
Taste: Salty
Table of contents:
Can potassium citrate desensitize teeth?
Yes, potassium citrate is a legitimate desensitizing agent in toothpaste and it will alleviate teeth sensitivity. It does so by depolarizing the tooth nerve which prevents it from firing sensitivity signals despite being exposed to stimuli.
There have been a plethora of studies which found a reduction in tooth sensitivity when potassium citrate is included as an ingredient. It also works in more than just toothpaste.
Study #1 - 85% of subjects found a reduction in sensitivity after 4 weeks of use.
Study #2 - Statistically significant reduction in dentin hypersensitivity after 8 weeks use of 5.53% potassium citrate toothpaste vs 0.76% sodium fluoride toothpaste.
Study #3 - Aside from toothpaste, it is even effective in a mouthwash formulation.
Desensitization mechanism
The way potassium citrate in toothpaste desensitizes teeth is identical to how potassium nitrate does it. They depolarize the tooth nerve by supplying an overabundance of potassium ions which inverts the concentration gradient thus preventing a signal from being fired.
In other words, it temporarily numbs your tooth. Although if you brush with it consistently, that numbing effect becomes quasi permanent.
Desensitization mechanism:
It is applied topically onto the tooth surface via toothpaste.
The potassium ions (K+) travel through the dentinal tubules to reach the nerve.
An overabundance of K+ reverses the natural concentration gradient which effectively prevents propagation of action potentials.
In other words, no pain signals can be fired.
Under normal circumstances without potassium citrate, there is a higher concentration of K+ inside the nerve cell and a lower one outside of it. Molecules typically move down the concentration gradient from high to low.
However, when you brush with a potassium citrate toothpaste, there is now an excess of K+ outside of the cell. This inverts the concentration gradient thus preventing the K+ ions from flowing outwards. This effectively stops the propagation of action potentials.
Ultimately, your tooth is still being stimulated by sensitive triggers but the nerve is just unable to send sensitivity signals to your brain. You can think of this desensitizing ingredient as a tooth numbing agent.
Side effects
No adverse effects from using toothpastes with potassium citrate have been reported.
However, other than toothpaste use it is the primary ingredient in medication used to treat kidney stones and acidic problems in blood. In those medications, side effects, precautions, and warnings are explicitly stated.
Allergic reaction - rash; hives; itching; red, swollen, blistered, or peeling skin with or without fever; wheezing; tightness in the chest or throat; trouble breathing, swallowing, or talking; unusual hoarseness; or swelling of the mouth, face, lips, tongue, or throat.
Signs of high potassium levels - irregular heartbeat; confusion; lightheaded, dizzy; feeling like passing out; numbness or tingling; or shortness of breath.
Feeling very tired or weak.
Swollen belly.
Black, tarry, or bloody stools.
Throwing up blood or vomit that looks like coffee grounds.
Stomach pain
Diarrhea.
Alternative toothpaste desensitizers
The most comparable alternative toothpaste desensitizing agent is potassium nitrate, which reduces teeth sensitivity via the same mechanism.
What is used to desensitize the teeth is the potassium ion that is attached to both ingredients. The only difference between these two desensitizers is that one is bound to citrate while the other is bound to nitrate. Aside from that, they are virtually identical for all intents and purposes.
Tubular occlusion agents
The potassium based toothpastes block sensitivity signals via nerve depolarization but there are other desensitizers which work via tubular occlusion.
How tubular occlusion desensitizers work:
These agents physically insert themselves into exposed dentinal tubules and block it.
That prevents stimuli from even interacting with the tooth nerve.
Essentially you can think of the tubular occluding desensitizers as a physical barrier which prevents stimuli from coming into contact with the nerves.
Types of tubular occluding agents:
Hydroxyapatite
Stannous fluoride
Stannous chloride
Arginine
Strontium chloride
Takeaway
The purpose of potassium citrate in toothpaste is to reduce teeth sensitivity by depolarizing the tooth nerve. It works identically to another toothpaste desensitizer, potassium nitrate (KNO3).
It is safe to use since no one swallows toothpaste. It is also not a novel ingredient since it has been used for a long time in kidney stone medications. That actually makes it safer as a toothpaste ingredient since you don't need to swallow it like in the medication form and ingest it.
That's everything that our dentists in Long Island City have to say about this desensitizing toothpaste ingredient.
